Friday, August 9, 2013

Welcome Swallows "fishing" at WTP

As happened in 2012, Welcome Swallows are again feeding on larvae captured from below the surface of the roadside pools on 29 Mile Rd at the WTP Western Lagoons at Werribee, Vic. About 30 were hovering over the pools and plunging their heads below the surface. I noticed that after each attack when the head had gone deep into the water the birds swung their heads 180º when they rose up. It appears that they do this to remove water from their faces. The head was not swung if only the bill entered the water.

I have received reports of this sub-surface feeding behaviour from Warrnambool, WTP, Dandenong and Anderson’s Inlet, all along the south coast of Victoria. Has anyone seen this type of feeding behaviour from any Hirundinidae species from any other place? NSW? SA? Central Vic? Overseas?

The photos below aren’t the best quality but have you ever tried to photograph a fast flying, zipping and dipping swallow and catch it, not only in focus but in focus at a precise milli-second over a shaded pond – and then maintain focus for a series of 3 or 4 photos as the bird moves? Aaaaagh! (smile). It's a fun challenge though so the next half decent day I will go back and try again.

There are so few flying insects at the WTP at the moment that swallows follow my car as I drive along grassy tracks hoping I disturb something. Maybe the diving takes place at this time of year because there is so little of the more easy to capture flying prey? 

The type of sub-surface prey captured may be opportunistic as to species as long as the length is acceptable because I have one out of focus photo that seems to show a round beetle and another, also out of focus, that may be a silver-coloured, very small (10 mm +/-) fish.

Welcome Swallows hunting for swimming prey. The bird on left has head in water, the centre bird is looking and the right hand bird has just struck at a prey.

Swallow capturing prey with bill just in the water

(1) First in a sequence of three photos taken within 1 second. The bird has seen prey and is about to strike ...

... (2) the catch has been made, apparently a larvae of some sort ...

... (3) and finally the bill is open and the prey can just be made out at the back of the mouth.

Head swing showing circle of water drops. The tail is kicked up so that it clears the water as the swallow rises after the attack.

This shows a more extreme example of the raised tail and 180º head rotation.

Could this be a very small silver-coloured fish? Or maybe just water shining on a larvae of some type? A better photo will be needed.

All images & text © Jenny Spry

1 comment:

  1. Your photos of the swallows are fantastic. I am currently snapping swallows as they dip on the surface of my dam. I am much further away but I think I'll have to move in closer after seeing your amazing photos. Bronwyn
    Ps. I live in NSW just over the border from Far East Gippsland. (Near Delegate)